Dimerization of the scavenger receptor class B type I

Autor: Eve Reaven, Yuan Cortez, Susan Leers-Sucheta, Ann Nomoto, Salman Azhar
Jazyk: angličtina
Rok vydání: 2004
Předmět:
Zdroj: Journal of Lipid Research, Vol 45, Iss 3, Pp 513-528 (2004)
Druh dokumentu: article
ISSN: 0022-2275
DOI: 10.1194/jlr.M300370-JLR200
Popis: This study has examined the dimeric/oligomeric forms of scavenger receptor class B type I (SR-BI) and its alternatively spliced form, SR-BII, in a diverse group of cells and tissues: i.e., normal and hormonally altered tissues of mice and rats as well as tissues of transgenic animals and genetically altered steroidogenic and nonsteroidogenic cells overexpressing the SR-B proteins. Using both biochemical and morphological techniques, we have seen that these dimeric and higher order oligomeric forms of SR-BI expression are strongly associated with both functional and morphological expression of the selective HDL cholesteryl ester uptake pathway. Rats and mice show some species differences in expression of SR-BII dimeric forms; this difference does not extend to the use of SR-B cDNA types for transfection purposes. In a separate study, cotransfection of HEK293 cells with cMyc and V5 epitope-tagged SR-BI permitted coprecipitation and quantitative coimmunocytochemical measurements at the electron microscope level, suggesting that much of the newly expressed SR-BI protein in stimulated cells dimerizes and that the SR-BI dimers are localized to the cell surface and specifically to microvillar or double membraned intracellular channels.These combined data suggest that SR-BI self-association represents an integral step in the selective cholesteryl ester uptake process.
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